Scaled symbols for a self-contained time division duplex (tdd) subframe structure

ABSTRACT

In an aspect of the disclosure, a method, a computer program product, and an apparatus are provided. The method may be performed by a scheduling entity. The scheduling entity transmits control information in a control portion of the subframe, the control information corresponding to data information within the subframe, transmits the data information in a data portion of the subframe, receives a pilot signal from the set of subordinate entities in a pilot portion of the subframe, and receives an ACK/NACK signal from the set of subordinate entities in an ACK portion of the subframe. The ACK portion is subsequent to the pilot portion of the subframe. The ACK/NACK signal includes acknowledgment information corresponding to the data information. The control portion, the data portion, the pilot portion, and the ACK portion are contained in the same subframe.

PRIORITY CLAIM

This application claims priority to and the benefit of provisionalpatent application Ser. No. 62/162,557 filed in the United States Patentand Trademark Office on May 15, 2015, the entire content of which isincorporated herein by reference.

TECHNICAL FIELD

Aspects of the present disclosure relate generally to wirelesscommunication systems, and more particularly, to scaling symbols forself-contained time division duplex (TDD) subframe structures.

BACKGROUND

Wireless communication systems are widely deployed to provide varioustelecommunication services such as telephony, video, data, messaging,and broadcasts. Typical wireless communication systems may employmultiple-access technologies capable of supporting communication withmultiple users by sharing available system resources (e.g., bandwidth,transmit power). Examples of such multiple-access technologies includecode division multiple access (CDMA) systems, time division multipleaccess (TDMA) systems, frequency division multiple access (FDMA)systems, orthogonal frequency division multiple access (OFDMA) systems,single-carrier frequency division multiple access (SC-FDMA) systems, andtime division synchronous code division multiple access (TD-SCDMA)systems.

These multiple access technologies have been adopted in varioustelecommunication standards to provide a common protocol that enablesdifferent wireless devices to communicate on a municipal, national,regional, and even global level. Examples of telecommunication standardinclude Long Term Evolution (LTE) and LTE-Advanced (LTE-A), whichinclude a set of enhancements to the Universal Mobile TelecommunicationsSystem (UMTS) mobile standard promulgated by Third GenerationPartnership Project (3GPP). It is designed to better support mobilebroadband Internet access by improving spectral efficiency, loweringcosts, improving services, making use of new spectrum, and betterintegrating with other open standards using OFDMA on the downlink (DL),SC-FDMA on the uplink (UL), and multiple-input multiple-output (MIMO)antenna technology. However, as the demand for mobile broadband accesscontinues to increase, there exists a need for further improvements inmultiple access technologies technology. Preferably, these improvementsshould be applicable to existing and developing multi-accesstechnologies and the telecommunication standards that employ suchtechnologies.

BRIEF SUMMARY OF SOME EXAMPLES

One aspect provides a method of wireless communication in a synchronousnetwork for a subordinate entity to communicate with a scheduling entityutilizing a time division duplex (TDD) carrier, where the TDD carrierincludes a subframe. The method includes receiving control informationin a control portion of the subframe, the control informationcorresponding to data information within the subframe, receiving thedata information in a data portion of the subframe, transmitting a pilotsignal to the scheduling entity in a pilot portion of the subframe, andtransmitting an acknowledged (ACK)/not acknowledged (NACK) signal to thescheduling entity in an ACK portion of the subframe, the ACK portionbeing subsequent to the pilot portion of the subframe, the ACK/NACKsignal comprising acknowledgment information corresponding to the datainformation. The control portion, the data portion, the pilot portion,and the ACK portion are contained in the same subframe.

In one example, the subframe includes a guard period portion after thedata portion and before the pilot portion, where a total duration of theguard period portion and the pilot portion is greater than or equal toan approximate duration of a full symbol in the subframe. In suchexample, the method further includes processing the data informationreceived in a final symbol of the data portion of the subframe withinthe total duration of the guard period portion of the subframe and thepilot portion of the subframe. For example, a duration of the guardperiod portion may be less than the duration of a full symbol in thesubframe. In one example, the subframe includes a second guard periodportion after the ACK portion of the subframe, where a duration of thesecond guard period portion is less than the duration of a full symbolin the subframe.

In one example, the pilot portion includes a first cyclic prefix (CP)and the ACK portion includes a second CP. In one example, a duration ofthe pilot portion of the subframe is different from a duration of theACK portion of the subframe.

One aspect of the present disclosure provides a method of wirelesscommunication in a synchronous network for a scheduling entity tocommunicate with a set of one or more subordinate entities utilizing aTDD carrier, where the TDD carrier includes a subframe. The methodincludes determining a downlink (DL) to uplink (UL) switching periodassociated with the one or more subordinate entities, determining asignal propagation delay period between the scheduling entity and theone or more subordinate entities, and dividing a full symbol in thesubframe into a plurality of scaled symbols, at least one of theplurality of scaled symbols having a duration that is equal to orgreater than a total of the DL to UL switching period and the signalpropagation delay period.

In one example, the at least one of the plurality of scaled symbolsserves as a guard period. In such example, the method further includestransmitting data information to the one or more subordinate entities inone or more of the plurality of scaled symbols.

In one example, each of the plurality of scaled symbols are allocatedless tones than the full symbol. In another example, each of theplurality of scaled symbols have a same duration, where in one examplethe scaled symbols have a scaled subcarrier spacing as the nominalsymbols to avoid the need for multiple sampling rates.

The following presents a simplified summary of one or more aspects ofthe present disclosure, in order to provide a basic understanding ofsuch aspects. This summary is not an extensive overview of allcontemplated features of the disclosure, and is intended neither toidentify key or critical elements of all aspects of the disclosure norto delineate the scope of any or all aspects of the disclosure. Its solepurpose is to present some concepts of one or more aspects of thedisclosure in a simplified form as a prelude to the more detaileddescription that is presented later.

These and other aspects of the disclosure will become more fullyunderstood upon a review of the detailed description, which follows.Other aspects, features, and embodiments of the present invention willbecome apparent to those of ordinary skill in the art, upon reviewingthe following description of specific, exemplary embodiments of thepresent invention in conjunction with the accompanying figures. Whilefeatures of the present invention may be discussed relative to certainembodiments and figures below, all embodiments of the present inventioncan include one or more of the advantageous features discussed herein.In other words, while one or more embodiments may be discussed as havingcertain advantageous features, one or more of such features may also beused in accordance with the various embodiments of the inventiondiscussed herein. In similar fashion, while exemplary embodiments may bediscussed below as device, system, or method embodiments it should beunderstood that such exemplary embodiments can be implemented in variousdevices, systems, and methods.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a diagram illustrating an example of a network architecture.

FIG. 2 is a block diagram illustrating a scheduling entity and aplurality of subordinate entities.

FIG. 3 illustrates a radio frame for wireless communication between thescheduling entity and the subordinate entity.

FIG. 4 illustrates an example structure of a self-contained subframe.

FIG. 5 illustrates an example structure of a self-contained subframe.

FIG. 6 illustrates the structure of a self-contained subframe inaccordance with some aspects of the present disclosure.

FIG. 7 illustrates the structure of self-contained subframes inaccordance with some aspects of the present disclosure.

FIG. 8 is a diagram illustrating the structure of self-containedsubframes in accordance with some aspects of the present disclosure.

FIG. 9 is a diagram illustrating an example symbol structureimplementing scaled symbols.

FIG. 10 is a diagram illustrating an example symbol structureimplementing scaled symbols.

FIG. 11 is a diagram illustrating an example of a hardwareimplementation of an apparatus 1102 according to some aspects of thepresent disclosure.

FIG. 12 is a diagram illustrating an example of various methods and/orprocesses according to aspects of the present disclosure.

FIG. 13 is a diagram illustrating an example of various methods and/orprocesses according to aspects of the present disclosure.

FIG. 14 is a diagram illustrating an example of various methods and/orprocesses according to aspects of the present disclosure.

FIG. 15 is a diagram illustrating an example of a hardwareimplementation of an apparatus according to various aspects of thepresent disclosure.

FIG. 16 is a diagram illustrating an example of various methods and/orprocesses according to aspects of the present disclosure.

DETAILED DESCRIPTION

The detailed description set forth below in connection with the appendeddrawings is intended as a description of various configurations and isnot intended to represent the only configurations in which the conceptsdescribed herein may be practiced. The detailed description includesspecific details for the purpose of providing a thorough understandingof various concepts. However, it will be apparent to those skilled inthe art that these concepts may be practiced without these specificdetails. In some instances, well known structures and components areshown in block diagram form in order to avoid obscuring such concepts.

Several aspects of telecommunication systems will now be presented withreference to various apparatus and methods. These apparatus and methodswill be described in the following detailed description and illustratedin the accompanying drawings by various blocks, modules, components,circuits, steps, processes, algorithms, etc. (collectively referred toas “elements”). These elements may be implemented using electronichardware, computer software, or any combination thereof. Whether suchelements are implemented as hardware or software depends upon theparticular application and design constraints imposed on the overallsystem.

FIG. 1 is a diagram illustrating a generalized example of an accessnetwork 100. In this example, the access network 100 is divided into anumber of cellular regions (cells) 102. One or more lower power classbase stations 108 may have cellular regions 110, 112 that overlap withone or more of the cells 102. The lower power class base stations 108may be a femto cell (e.g., pico cell, micro cell, remote radio head, orin some instances, another user equipment (UE) 106 (as illustratedgenerally as the mesh network 112). The base stations 104 are eachassigned to a respective cell 102 and are configured to provide anaccess point to a core network for all the UEs 106 in the cells 102.There is no centralized controller in this example of an access network100, but a centralized controller may be used in alternativeconfigurations. The base stations 104 are responsible for all radiorelated functions including radio bearer control, admission control,mobility control, scheduling, security, and connectivity to the servinggateway 116.

The modulation and multiple access scheme employed by the access network100 may vary depending on the particular telecommunications standardbeing deployed. In some radio access networks, such as those definedaccording to the evolved packet system (EPS) or long-term evolution(LTE), orthogonal frequency division multiplexing (OFDM) may be used onthe downlink (DL) and single-carrier frequency division multiple access(SC-FDMA) may be used on the uplink (UL) to support both frequencydivision duplexing (FDD) and time division duplexing (TDD). As thoseskilled in the art will readily appreciate from the detailed descriptionto follow, the various concepts presented herein are well suited forvarious applications including telecommunication standards employingother modulation and multiple access techniques. By way of example,these concepts may be employed in future fifth-generation (5G)standards, LTE, Evolution-Data Optimized (EV-DO) or Ultra MobileBroadband (UMB). EV-DO and UMB are air interface standards promulgatedby the 3rd Generation Partnership Project 2 (3GPP2) as part of theCDMA2000 family of standards, employing code division multiple access(CDMA) to provide broadband Internet access to mobile stations. Theseconcepts may also be extended to Universal Terrestrial Radio Access(UTRA) employing Wideband-CDMA (W-CDMA) and other variants of CDMA, suchas TD-SCDMA; Global System for Mobile Communications (GSM) employingTDMA; and Evolved UTRA (E-UTRA), IEEE 802.11 (Wi-Fi), IEEE 802.16(WiMAX), IEEE 802.20, and Flash-OFDM employing OFDMA. UTRA, E-UTRA,UMTS, LTE and GSM are described in documents from the 3GPP organization.The actual wireless communication standard and the multiple accesstechnology employed will depend on the specific application and theoverall design constraints imposed on the system.

The base stations 104 may have multiple antennas supporting MIMOtechnology. The use of MIMO technology enables the base stations 104 toexploit the spatial domain to support spatial multiplexing, beamforming,and transmit diversity. Spatial multiplexing may be used to transmitdifferent streams of data simultaneously on the same frequency. The datasteams may be transmitted to a single UE 106 to increase the data rateor to multiple UEs 106 to increase the overall system capacity. This isachieved by spatially precoding each data stream (i.e., applying ascaling of an amplitude and a phase) and then transmitting eachspatially precoded stream through multiple transmit antennas on the DL.The spatially precoded data streams arrive at the UE(s) 106 withdifferent spatial signatures, which enables each of the UE(s) 106 torecover the one or more data streams destined for that UE 106. On theUL, each UE 106 transmits a spatially precoded data stream, whichenables the base stations 104 to identify the source of each spatiallyprecoded data stream.

Spatial multiplexing is generally used when channel conditions are good.When channel conditions are less favorable, beamforming may be used tofocus the transmission energy in one or more directions. This may beachieved by spatially precoding the data for transmission throughmultiple antennas. To achieve good coverage at the edges of the cell, asingle stream beamforming transmission may be used in combination withtransmit diversity.

Certain aspects of an access network described herein may relate to aMIMO system supporting OFDM on the DL. OFDM is a spread-spectrumtechnique that modulates data over a number of subcarriers within anOFDM symbol. The subcarriers are spaced apart at precise frequencies.The spacing provides “orthogonality” that enables a receiver to recoverthe data from the subcarriers. In the time domain, a guard interval(e.g., cyclic prefix or CP) may be added to each OFDM symbol to combatinter-OFDM-symbol interference. The UL may use SC-FDMA in the form of aDFT-spread OFDM signal to compensate for high peak-to-average powerratio (PAPR).

Referring now to FIG. 2, a block diagram illustrates a scheduling entity202 communicating with a plurality of subordinate entities 204 utilizinguplink and downlink data and control channels. For example, thescheduling entity 202 may be a base station, Node B, eNode B, networkaccess point, etc. As another example, the scheduling entity 202 may bea UE in a device-to-device (D2D) and/or mesh network. The schedulingentity 202 manages the resources on the carrier and assigns resources toother users of the channel, including subordinate or scheduled entitiesin a cellular network. For example, the subordinate entities 204 may beUEs or Internet of everything (IOE) devices. Of course, the channelsillustrated in FIG. 2 are not necessarily all of the channels that maybe utilized between a scheduling entity 202 and subordinate entities204, and those of ordinary skill in the art will recognize that otherchannels may be utilized in addition to those illustrated, such as otherdata, control, and feedback channels.

As illustrated in FIG. 2, the scheduling entity 202 may broadcastdownlink data 206 to one or more subordinate entities 204. In accordancewith certain aspects of the present disclosure, the term downlink mayrefer to a point-to-multipoint transmission originating at thescheduling entity 202. Broadly, the scheduling entity 202 is a node ordevice responsible for scheduling traffic in a wireless communicationnetwork, including the downlink transmissions and, in some examples,uplink data 210 from one or more subordinate entities to the schedulingentity 202. (Another way to describe the scheme may be to use the termbroadcast channel multiplexing.) In accordance with aspects of thepresent disclosure, the term uplink may refer to a point-to-pointtransmission originating at a subordinate entity 204. Broadly, thesubordinate entity 204 is a node or device that receives schedulingcontrol information, including but not limited to scheduling grants,synchronization or timing information, or other control information fromanother entity in the wireless communication network such as thescheduling entity 202.

The scheduling entity 202 may broadcast a control channel 208 to one ormore subordinate entities 204. Uplink data 210 and/or downlink data 206may be transmitted using a transmission time interval (TTI). Here, a TTImay correspond to an encapsulated set or packet of information capableof being independently decoded, i.e., the shortest decodabletransmission of information. In various examples, TTIs may correspond toframes, to data blocks, time slots, or other suitable groupings of bitsfor transmission.

Furthermore, the subordinate entities 204 may transmit a feedbackchannel 214 to the scheduling entity 202. The feedback channel 214 mayin some examples include a request for the scheduling entity to scheduleuplink transmissions. Here, in response to the request transmitted onthe feedback channel 214, the scheduling entity 202 may transmit in thecontrol channel 212 information that may schedule the TTI with uplinkpackets. In a further example, the feedback channel 214 may includeinformation about interference experienced at the subordinate entity204, which the scheduling entity 202 may utilize dynamically to modifydownlink transmissions in a way that may make further downlinktransmissions more robust to the interference.

FIG. 3 illustrates an example of a radio frame 300 that may be used forwireless communication between the scheduling entity 202 and thesubordinate entity 204. In an aspect of the present disclosure, theradio frame 300 may have a time duration 302. For example, the timeduration 302 may be 5 ms. Further, the radio frame 300 may include oneor more subframes (SFs). In the example configuration of FIG. 3, theradio frame 300 includes 10 subframes (e.g., labeled “SF0” to “SF9” inFIG. 3) that have the same time duration 304. For example, the timeduration 304 may be 500 μs. However, within the scope of the presentdisclosure, a frame may include any suitable number of subframes, andeach subframe may have any suitable duration. In some aspects of thepresent disclosure, one or more of the subframes SF0 to SF9 may beself-contained subframes, described below.

For example, FIG. 4 illustrates one example structure of aself-contained subframe 400. In the illustrated example, a subframe maybe a transmitter-scheduled subframe, referred to herein as adownlink-centric subframe or DL-centric subframe, as more resources areallocated for transmissions in the downlink direction (e.g.,transmissions from the scheduling entity 202 to the subordinate entity204).

Each subframe, such as subframe 400, may include transmit (Tx) andreceive (Rx) portions. For example, in the DL-centric subframe 400, thescheduling entity 202 first has an opportunity to transmit controlinformation, e.g., on a physical downlink control channel (PDCCH) in thecontrol information portion 402, and then an opportunity to transmitdata information, e.g., on a physical downlink shared channel (PDSCH) inthe DL data portion 404. Following a guard period (GP) portion 406having a suitable duration 410, the scheduling entity 202 has anopportunity to receive an acknowledged (ACK)/not acknowledged (NACK)signal in the ACK portion 408 from other entities using the carrier.Here, a subframe such as the subframe 400 may be referred to as aself-contained subframe when all of the data carried in the data portion404 of the subframe 400 is scheduled in the control portion 402 of thesubframe, and further, when all of the data carried in the data portion404 of the subframe 400 is acknowledged (or at least has an opportunityto be acknowledged) in the ACK portion 408 of the subframe 400. In thisway, each self-contained subframe may be considered a self-containedentity, not necessarily requiring any other subframe to complete ascheduling-transmission-acknowledgment cycle for any given packet.

The GP portion 406 may be included to accommodate variability in UL andDL timing. For example, latencies due to radio frequency (RF) antennadirection switching (e.g., from DL to UL) and transmission pathlatencies may cause the subordinate entity 204 to transmit early on theUL to match DL timing. Such early transmission may interfere withsymbols received from the scheduling entity 202. Accordingly, the GPportion 406 may allow an amount of time after the DL data portion 404 toprevent interference, where the GP portion 406 provides an appropriateamount of time for the scheduling entity 202 to switch its RF antennadirection, an appropriate amount of time for the over-the-air (OTA)transmission, and an appropriate amount of time for ACK processing bythe subordinate entity.

Therefore, the GP portion 406 provides an appropriate amount of time forthe subordinate entity 204 to switch its RF antenna direction (e.g.,from DL to UL), to processes the data payload, and for the OTAtransmission time. The duration of the GP portion 406 may be configuredin terms of full symbol periods. For example, the GP portion 506 mayhave a duration of one full symbol period (e.g., 31.25 μs).

FIG. 5 illustrates another example structure of a self-containedsubframe 500 (also referred to as DL-centric subframe 500). As seen, thestructure of the DL-centric subframe 500 is essentially the same as thatof the subframe 400 illustrated in FIG. 4 and described above, exceptfor a timing advance (TA) command has been applied to the UL waveform(e.g., the ACK portion 508). With reference to the DL-centric subframe500, the scheduling entity 202 first has an opportunity to transmitcontrol information in the control information portion 502, and then anopportunity to transmit data information in the DL data portion 504.Following the GP portion 506, the scheduling entity has an opportunityto receive an ACK/NACK signal in the ACK portion 508 from other entities(e.g., subordinate entity 204) using the carrier. A second GP portion510 is subsequent to the ACK portion 508.

A timing advance command may be sent from the scheduling entity 202 tothe subordinate entity 204 in order to correct the timing of thesubordinate entity 204 relative to a current timing of the subordinateentity 204. For example, in response to a TA command, the subordinateentity 204 may delay its timing (e.g., transmit later relative to thecurrent timing of the subordinate entity 204) or advance its timing(e.g., transmit earlier relative to the current timing of thesubordinate entity 204) to compensate for a propagation delay betweenthe scheduling entity 202 and the subordinate entity 204. Therefore, inthe example configuration of DL-centric subframe 500 in FIG. 5, a TAcommand has advanced the timing of the subordinate entity 204 such thatthe ACK portion 508 (e.g., UL portion) of the subframe is configuredearlier relative to its current timing. As such, the GP duration 512 ofGP portion 506 in FIG. 5 is reduced relative to the GP duration 410 ofGP 406 in FIG. 4 (e.g., where no TA command is applied). In the exampleconfiguration of the DL-centric subframe 500 in FIG. 5, the periodremaining in the DL-centric subframe 500 subsequent to the ACK portion508 is allocated as a guard period (e.g., the second GP portion 510).Accordingly, the first duration 512 of GP portion 506 and the secondduration 514 of the second GP portion 510 may each be less than one fullsymbol period.

One consequence of the timing advance illustrated in FIG. 5 is acompression of the processing timeline for calculating theacknowledgment information for transmission in the ACK portion 508. Thatis, the receiving subordinate entity 204 may apply a suitable errorchecking algorithm to packets received in the data portion 504, in orderto determine whether to acknowledge or not those packets in the ACKportion 508. In order to timely process the data payload received duringthe DL data portion 504 to sustain stable throughput, the subordinateentity 204 will require sufficient processing time to generate the ACKsymbols as the data payload is received. However, especially with thetiming advance discussed above, since the GP portion 506 has a durationthat may be less than one symbol period, the subordinate entity 204 maynot have sufficient time to process the data payload received during thelast full symbol in the DL data portion 504 before a control channelsymbol is formed.

FIG. 6 illustrates the structure of a self-contained subframe 600 inaccordance with some aspects of the present disclosure. As shown in FIG.6, the self-contained subframe 600 includes a control informationportion 602, a DL data portion 604, a first GP portion 606, an ACKportion 608, and a second GP portion 609. As further shown in FIG. 6,the horizontal axis relative to the self-contained subframe 600represents time and the vertical axis relative to the self-containedsubframe 600 represents frequency. In the configuration of FIG. 6, theself-contained subframe 600 has a duration of 16 symbol periods (e.g.,symbols 0 through 15 indicated at the top of the self-contained subframe600). For example, each of the 16 symbol periods may be full OFDM symbolperiods. Accordingly, the DL control information portion 602 has aduration of one full symbol period, the DL data portion 604 has aduration of 13 full symbol periods, the first guard period portion 606has a duration that is less than one full symbol period, the ACK portion608 has a duration of one full symbol period, and the second guardperiod portion 609 has a duration that is less than one full symbolperiod. The structure of the self-contained subframe 600 during symbols14 and 15 may vary from this structure according to some aspects of thepresent disclosure. Here, the control information portion 602, DL dataportion 604, the first GP portion 606, the ACK portion 608, and thesecond GP portion 609 in FIG. 6 respectively correspond to the controlinformation portion 502, DL data portion 504, the first GP portion 506,the ACK portion 508, and the second GP portion 510 in FIG. 5.

As shown in FIG. 6, the scheduling entity 202 may configure the last twofull symbols of the self-contained subframe 600 (e.g., symbols 14 and15) using a first configuration or a second configuration. For example,the GP portion 610 may have a first duration 620 and the GP portion 616may have a second duration 622. Here, the first duration 620 mayrepresent the available processing time for the subordinate entity 204and the second duration 622 may represent the available processing timefor the scheduling entity 202. In one example, the first duration 620and the second duration 622 may each be one half of a full symbol.Therefore, in one example, if one full symbol is configured to have aduration of approximately 33.0 μs, the first and second durations 620,622 may each be approximately 16.5 μs. As shown in FIG. 6, the ACKportion 608 may be configured as the pilot and ACK portion 614 thatincludes a pilot signal and an ACK/NACK signal, and a cyclic prefix (CP)portion 612 that includes a CP. For example, the third duration 621 maybe equal to one full symbol period.

In order for the subordinate entity 204 to process the portion of thedata payload received during the last full symbol (e.g., symbol 13) inDL data portion 604, the subordinate entity 204 may require an amount ofprocessing time that is greater than or equal to the approximateduration of the last full symbol (e.g., the required processing time maybe less than a full symbol duration, but relatively close to a fullsymbol duration, e.g., within about 10% of a full symbol duration).However, since the first duration 620 of the GP portion 610 inconfiguration 1 is less than the duration of one full symbol period, thefirst duration 620 may not provide the subordinate entity 204 asufficient amount of processing time. It should be understood that inthe example of FIG. 6, with configuration 1, the subordinate entity 204is configured to complete processing of the entire data payload receivedin the DL data portion 604 prior to configuring and transmitting thepilot and ACK/NACK signal in the pilot and ACK portion 614 and the CP inthe CP portion 612.

In the second configuration (also referred to as configuration 2), theACK portion 608 may be configured as two separate scaled symbols (alsoreferred to as short symbols or scaled symbols) that are each shorter induration than one full symbol period. For example, the ACK portion 608may be configured as a first scaled symbol 625 including a CP portion626 and a pilot signal portion 628, and as a second scaled symbol 629that includes a CP portion 630 and an ACK portion 632. As shown in FIG.6, with configuration 2, the first scaled symbol 625 may have a thirdduration 638 and the second scaled symbol 629 may have a fourth duration640. In some examples, the third duration 638 may be different from thefourth duration 640. In a further example, the total of the firstduration 636 and the third duration 638 may be greater than or equal toone full symbol period. For example, the total of the first duration 636and the third duration 638 may be 33.86 μs. In a further aspect of thedisclosure, the overhead introduced by the CP in the CP portion 630 maybe reduced by reducing the size of the CP or by omitting the CP.

In this way, by time dividing the pilot from the ACK portions, thesubordinate entity 204 is not required to complete processing of theentire data payload received in the DL data portion 604 prior toconfiguring and transmitting a pilot signal. As such, the subordinateentity 204 may use the third duration 638 of the first scaled symbol 625in addition to the first duration 636 of the first GP portion 624 toprocess the portion of the data payload received during the last fullsymbol (e.g., symbol 13) in the DL data portion 604. Since the total(e.g., fifth duration 644) of the first duration 636 and the thirdduration 638 may be greater than or equal to one full symbol period,configuration 2 provides the subordinate entity 204 adequate time toprocess the portion of the data payload received during the last fullsymbol (e.g., symbol 13) prior to configuring and transmitting the CP inthe CP portion 630 and the ACK/NACK signal in the ACK portion 632. Itshould be noted that although the second duration 642 is less than onefull symbol period, the second duration 642 of the second GP portion 634can still provide the scheduling entity 202 adequate time to switch itsRF antenna direction and for any associated overhead involved inperforming such switching of its RF antenna direction. For example, thesecond duration 642 may be 12.2 μs.

In an aspect of the present disclosure, the total UL transmission powerfor the pilot signal in the pilot signal portion 628 and the ACK/NACKsignal in the ACK portion 632 of configuration 2 may be equal to the ULtransmission power for the pilot and ACK/NACK signal of the pilot andACK portion 614 in configuration 1. In another aspect of the disclosure,configuration 2 may provide a lower peak to average power ratio (PAPR)than configuration 1. In some examples, the pilot signal of the pilotsignal portion 628 may be used for automatic gain control training. Insome examples, the sampling rate of the pilot signal in the pilot signalportion 628 and the sampling rate of the ACK/NACK signal in 608 may bethe same as the sampling rate of the pilot and ACK/NACK signal in thepilot and ACK portion 614.

In a further aspect of the disclosure, the same structure applied in theself-contained subframe 600 in FIG. 6 may be applied to UL control anddata. Alternatively, UL control and data may be based on differentlyscaled symbol structures. For example, the data and control symbols maybe separated by a guardband. As another example, weighted overlap andadd (WOLA) may be applied to the data and control symbols to controlinter-carrier interference (ICI).

In configuration 2 of FIG. 6, one or more of the scaled symbols (e.g.,third and fourth durations 638, 640) may be configured to omit the CP toreduce overhead. Moreover, each scaled symbol may achieve finegranularity for low-latency/fast TDD switching without substantiallyincreasing the nominal CP overhead. It should be noted that inconventional TDD frame structures, the duration of GP portions areconfigured based on a number of full OFDM symbol(s). As such, theoverhead (e.g., duration) allocated for DL/UL switching in suchconventional TDD frame structures is based on one or more full OFDMsymbol durations, and not the actual time required to perform DL/ULswitching and any propagation delay period between a scheduling entityand a subordinate entity. For example, the actual DL/UL switchingoverhead may be determined based on equation 1:

DL/UL switching overhead=RE switching time+2*OTA delay   (equation 1)

where the DL/UL switching overhead represents the actual DL/UL switchduration of the scheduling entity 202, RE switching time represents theduration required for the scheduling entity 202 to change its RF antennadirection, and the OTA delay represents the propagation delay betweenthe scheduling entity 202 and the subordinate entity 204. For example,if the RF switching time for a scheduling entity 202 is 5.0 μs and theOTA delay value with respect to a subordinate entity 204 at 1.0 km fromthe scheduling entity 202 is 3.3 μs, then the DL/UL switching overheadfor the scheduling entity 202 may be determined to be 11.3 μs (e.g., 5.0μs+2(3.3 μs)). It should be noted that the term “2* OTA delay”represents the round trip time (RTT) of a signal. Therefore, theallocation of a GP portion having a duration of one full OFDM symbol(e.g., 70.0 μs or 31.25 μs) as done in conventional TDD frame structuresmay be substantially more than the actual DL/UL switching overhead(e.g., 11.3 μs). Additional data may be transmitted with a scaled symbolof the nominal symbol (e.g. ½). The same technique applies when anextended CP (e.g., for a larger cell radius) is implemented.

In one example, the scheduling entity 202 may apply a TA command of 30μs for users (e.g., subordinate entities 204) on the cell edge. In thiscase, a self-contained subframe structure may be designed where thenumber of symbols in the UL portion is a function of the OTA delaybetween subordinate entity (e.g., subordinate entity 204) and thescheduling entity (e.g., scheduling entity 202). Users at the cell edgemay have fewer UL symbols, providing a sufficient gap for the OTA delay.Users near the scheduling entity 202 may utilize more UL symbols toachieve a higher throughput.

FIG. 7 illustrates the structure of self-contained subframes 701 and 703in accordance with some aspects of the present disclosure. Atransmitter-scheduled subframe, referred to herein as a downlink-centricsubframe or DL-centric subframe, may be used to carry a cell specificreference signal (CRS), control information, data information and/orscheduling information to a subordinate entity (e.g., subordinate entity204), which may be a UE for example.

Each subframe in FIG. 7 is divided into transmit (Tx) and receive (Rx)portions. In the DL-centric subframe 701, the scheduling entity 202first has an opportunity to transmit the CRS in the CRS portion 702,control information in the control information portion 704, and anopportunity to transmit data information in the DL data portion 706.Following a guard period (GP) portion 708, the scheduling entity has anopportunity to receive a pilot signal in pilot signal portion 710 and anACK/ NACK signal in the ACK portion 712 from other entities using thecarrier. A GP portion 714 is subsequent to the ACK portion 712. Thisframe structure is downlink-centric, as more resources are allocated fortransmissions in the downlink direction (e.g., transmissions from thescheduling entity 202 to the subordinate entity 204). As shown in FIG.7, the DL-centric subframe 703 is configured similar to DL-centricsubframe 701.

From the perspective of the subordinate entity 204, the UL pilot signalin the pilot signal portion 710 may be formed without completingprocessing of the data information received in the DL data portion 706.That is, formation of the ACK/NACK signal depends upon the results ofthe data processing. In the configuration of FIG. 7, the pilot signalportion 710 and the ACK portion 712 are configured by splitting anACK/NACK symbol having a duration of one full OFDM symbol into twoscaled symbols. The two scaled symbols (e.g., the pilot signal portion710 and the ACK portion 712) help to extend the subordinate entityprocessing timeline by a duration of one half of a full OFDM symbol.

From the perspective of the scheduling entity 202, the DL CRS waveform(e.g., CRS in the CRS portion 716) may be formed without completingprocessing of the ACK/NACK signal received from the subordinate entity204 in the ACK portion 712. In one example, only formation of thecontrol information signal depends upon the results of the dataprocessing. In the configuration of FIG. 7, the CRS portion 716 and thecontrol information portion 718 are configured by splitting a PDCCHcontrol symbol having a duration of one full OFDM symbol into two scaledsymbols. The two scaled symbols (e.g., the CRS portion 716 and thecontrol information portion 718) help to extend the scheduling entityprocessing timeline by a duration of one half of a full OFDM symbol.However, in some examples, the split symbol may require separate CPoverhead for the first two symbols, which would in turn eat into the GPin the same TTI.

In a further aspect of the disclosure, a similar technique may beapplied to the first symbol or symbols of a subframe, to relax theprocessing timeline at the scheduling entity 202. For example, FIG. 8 isa diagram 800 illustrating another example of the structure ofself-contained subframes 801 and 803 in accordance with some aspects ofthe present disclosure. The self-contained subframe 801 includes acontrol information portion (e.g., symbol 0), DL data portion (e.g.,symbols 2-6 and 9-13), GP portion (e.g., symbol 14), and a pilot and ACKportion 802 (e.g., symbol 15). As shown in FIG. 8, the horizontal axisrelative to the self-contained subframes 801 and 803 represents time andthe vertical axis relative to the self-contained subframes 801 and 803represents frequency. In the configuration of FIG. 8, the self-containedsubframe 801 has a duration of 16 symbol periods (e.g., symbols 0through 15 indicated at the top of the self-contained subframe 801). Forexample, each of the 16 symbol periods may be full OFDM symbol periods.

As shown in FIG. 8, the scheduling entity 202 may receive a pilot and anACK/NACK signal from the subordinate entity 204 in pilot and ACK portion802 of the self-contained subframe 801. In the subsequent self-containedsubframe 803, the scheduling entity 202 may configure the first symbol804 (e.g., symbol 0) using a first configuration or a secondconfiguration. For example, in the first configuration (also referred toas configuration 1), the first symbol 804 (e.g., symbol 0) may beconfigured to include a CP 808 and a cell specific reference signal(CRS) and control information portion 810 that includes a CRS andcontrol information (Ctrl). In one example, a GP portion 806 may precedethe first symbol 804. In configuration 1, the first duration 814 of theCP 808 and the CRS and control information portion 810 may beapproximately one full OFDM symbol period. In another example, the firsttwo symbols may have a scaled numerology or subcarrier spacing relativeto the nominal symbol, where each requires a CP of the same length asnominal symbol, which will reduce the GP duration in the TTI.

In order for the scheduling entity 202 to process the ACK/NACK signalreceived in the pilot and ACK portion 802 of the self-contained subframe801, the scheduling entity 202 may require an amount of processing timethat is greater than or equal to the duration of the pilot and ACKportion 802 (e.g., the duration of symbol 15 in self-contained subframe801 or less than the duration of symbol 15 if less than one full symbolis allocated for transmission of the ACK/NACK signal). However, theduration of the GP portion 806 in configuration 1 may be less than theduration of one full OFDM symbol period, which may not provide thescheduling entity 202 the required processing time. It should beunderstood that the scheduling entity 202 completes processing of theACK/NACK signal received in the pilot and ACK portion 802 beforeconfiguring and transmitting the CP 808 and the CRS and controlinformation in the CRS and control information portion 810.

In the second configuration (also referred to as configuration 2), forexample, the first symbol 804 may be split into and configured as twoseparate scaled symbols (also referred to as short symbols or partialsymbols) that are each shorter in duration than one full OFDM symbolperiod. For example, the first symbol 804 may be configured as a firstscaled symbol 817 including a CP portion 818 and a CRS portion 820, andas a second scaled symbol 821 that includes a CP portion 822 and acontrol portion 824. As shown in FIG. 8, the first scaled symbol 817 mayhave a first duration 826 and the second scaled symbol 821 may have asecond duration 828. In some examples, the first duration 826 may bedifferent from the second duration 828. In some examples, the total ofthe first duration 826 and the second duration 828 may be greater thanor equal to one full OFDM symbol period. For example, the total of thefirst duration 826 and the second duration 828 may be 33.86 μs. In someexamples, the overhead introduced by the CP in the CP portion 822 may bereduced by reducing the size of the CP or by omitting the CP.

The scheduling entity is not required to complete processing of theACK/NACK signal received in the pilot and ACK portion 802 prior toconfiguring and transmitting the CRS. As such, the scheduling entity 202may use the first duration 826 of the first scaled symbol 817 inaddition to the GP duration 825 in the GP portion 816 to process theACK/NACK signal (or other information) received during the last fullsymbol (e.g., symbol 15) in self-contained subframe 801. Since the totalof the GP duration 825 and the first duration 826 may be greater than orequal to one full OFDM symbol period (or greater than or equal to aduration of a scaled symbol used to transmit the ACK/NAK signal),configuration 2 can provide the scheduling entity 202 adequate time toprocess the ACK/NACK signal (or other information) received from thesubordinate entity 204 during the last symbol (e.g., symbol 15) prior toconfiguring and transmitting the CP in the CP portion 822 and thecontrol information in the control portion 824.

The manner in which one full OFDM symbol may be scaled down to providemultiple scaled symbols is described in greater detail with respect tothe example configurations in FIGS. 9 and 10 below.

FIG. 9 is a diagram illustrating an example symbol structureimplementing scaled symbols (also referred to as short symbols orpartial symbols) according to some aspects of the present disclosure.FIG. 9 shows a full OFDM symbol 904 having a duration of 28 is with anormal cyclic prefix (NCP) 902 having a duration of 3.5 μs. As shown inFIG. 9, the full OFDM symbol 904 has a subcarrier spacing (DO of 36 kHz.As further shown in FIG. 9, the full OFDM symbol 904 may be scaled(e.g., divided) down by a factor of two to generate two scaled symbols908 and 910 with an NCP 906. Accordingly, each of the two scaled symbols908 and 910 has a duration of 14 μs, but with a wider subcarrier spacing(e.g., 72 kHz) than the full OFDM symbol 904.

FIG. 10 is a diagram illustrating a symbol structure implementinganother example of scaled symbols according to some aspects of thepresent disclosure. FIG. 10 shows a full OFDM symbol 1004 having aduration of 28 μs with an NCP 1002 having a duration of3.5 μs. As shownin FIG. 10, the full OFDM symbol 1004 has a subcarrier spacing of 36kHz. As further shown in FIG. 10, the full OFDM symbol may be scaled(e.g., divided) down by a factor of three to generate three scaledsymbols 1008, 1010, and 1012 with an NCP 1006. Accordingly, each of thescaled symbols 1008, 1010, and 1012 has a duration of approximately 9.3μs, but with a wider subcarrier spacing (e.g., 108 kHz) than the fullOFDM symbol 1004.

In one example, every other tone in one full OFDM symbol may be zero andthe full OFDM symbol may generate a periodic time domain waveform. Inone example, a transmitter (e.g., subordinate entity 204) maysynchronously transmit a portion of a waveform, which may be sufficientto ensure demodulation and decoding without intercarrier interference(ICI) and/or intersymbol interference (ISI). A receiver (e.g.,scheduling entity 202) may receive and process the portion of thewaveform (e.g., the scaled symbol) using a smaller fast Fouriertransform (FFT) size or using zero padding or waveform repetition. Suchexample allows half usable tones in one full OFDM symbol at half of thepower of the full OFDM symbol. For example, and as described below withreference to FIG. 10, one full OFDM symbol may be split into threeseparate symbols to form a DL scaled symbol, a UL scaled symbol, and aGP scaled symbol, where the size of the DL scaled symbol is one half ofthe full OFDM symbol, the size of the UL scaled symbol is one quarter ofthe full OFDM symbol, and the size of the GP is one quarter of the fullOFDM symbol. For example, one quarter of the full OFDM symbol may have aduration of 6.0 μs.

The scaled symbols disclosed herein provide fine symbol granularity toachieve efficient DL/UL switching. Synchronous transmission effectivelymanages UL/DL interference. Therefore, by implementing the variousaspects disclosed herein, a scheduling entity and/or a subordinateentity may substantially reduce the DL/UL switching time. For example,since the DL/UL switching time is typically rounded up to one full OFDMsymbol in conventional schemes, the use of scaled symbols as disclosedherein may reduce DL/UL switching times to one half of the duration of afull OFDM symbol or shorter. As such, a 50% reduction or more in DL/ULswitching overhead may be achieved. For example, the duration of onefull OFDM symbol may be scaled down to serve as a scaled DL symbol,DL/UL switch period, and a scaled UL symbol. The same technique may beapplied to gain ACK/Ctrl decoding timeline to achieve a fast HARQturnaround.

FIG. 11 is a diagram illustrating an example of a hardwareimplementation of an apparatus 1102 according to various aspects of thepresent disclosure. Generally, the apparatus 1102 may be any deviceconfigured for wireless communication. In some configurations, theapparatus 1102 may be the scheduling entity 202, as described above. Theapparatus 1102 may include a user interface 1112. The user interface1112 may be configured to receive one or more inputs from a user of theapparatus 1102. The user interface 1112 may also be configured todisplay information to the user of the apparatus 1102. The userinterface 1112 may exchange data via the bus interface 1108.

The apparatus 1102 may also include a transceiver 1110. The transceiver1110 may be configured to receive data and/or transmit data incommunication with another apparatus. The transceiver 1110 provides ameans for communicating with another apparatus via a wired or wirelesstransmission medium. In some configurations, the transceiver 1110 mayprovide the means for communicating with various other apparatus over atransmission medium. According to aspects of the present disclosure, theterm(s) ‘communicate’ and/or ‘communicating’ refer to at least one of atransmission or a reception. In other words, without deviating from thescope of the present disclosure, the term(s) ‘communicate’ and/or‘communicating’ may refer to a transmission without asimultaneous/concurrent reception, a reception without asimultaneous/concurrent transmission, and/or a transmission with asimultaneous/concurrent reception.

In some examples, the transceiver 1110 may provide the apparatus 1102with the means for transmitting data (e.g., control information, datainformation, and/or reference signals) to the subordinate entity 204 aswell as the means for receiving data (e.g., pilot signals, ACK/NACKsignals) from subordinate entity 204. The transceiver 1110 may beconfigured to perform such communications using various types oftechnologies, as described in greater detail above. One of ordinaryskill in the art will understand that many types of technologies mayperform such communication without deviating from the scope of thepresent disclosure.

The apparatus 1102 may also include a memory 1105, one or moreprocessors 1104, a computer-readable medium 1106, and a bus interface1108. The bus interface 1108 may provide an interface between a bus 1103and the transceiver 1110. The memory 1105, the one or more processors1104, the computer-readable medium 1106, and the bus interface 1108 maybe connected together via the bus 1103. The processor 1104 may becommunicatively coupled to the transceiver 1110 and/or the memory 1105.

The processor 1104 may include a control information transmittingcircuit 1140.

In one example, the control information transmitting circuit 1140 mayinclude various hardware components and/or may perform variousalgorithms that provide the means for transmitting control informationin a control portion of a subframe, the control informationcorresponding to data information within the subframe. In anotherexample, the control information transmitting circuit 1140 may includevarious hardware components and/or may perform various algorithms thatprovide the means for transmitting control information in a controlinformation portion of a second subframe that is subsequent to thereference signal portion of the second subframe, wherein a duration ofthe control information portion is less than the duration of a fullsymbol in the second subframe.

The processor 1104 may also include a data information transmittingcircuit 1142. The data information transmitting circuit 1142 may includevarious hardware components and/or may perform various algorithms thatprovide the means for transmitting the data information in a dataportion of a subframe.

The processor 1104 may also include a pilot signal receiving circuit1144. The pilot signal receiving circuit 1144 may include varioushardware components and/or may perform various algorithms that providethe means for receiving a pilot signal from the set of subordinateentities in a pilot portion of the subframe.

The processor 1104 may also include an ACK/NACK signal receiving circuit1146. In one example, the ACK/NACK signal receiving circuit 1146 mayinclude various hardware components and/or may perform variousalgorithms that provide the means for receiving an ACK/NACK signal fromthe set of subordinate entities in an ACK portion of the subframe, theACK portion being subsequent to the pilot portion of the subframe, theACK/NACK signal including acknowledgment information corresponding tothe data information. In another example, the ACK/NACK signal receivingcircuit 1146 may include various hardware components and/or may performvarious algorithms that provide the means for receiving a first ACK/NACKsignal from a set of subordinate entities in a first subframe. In suchexample, the ACK/NACK signal receiving circuit 1146 may also includevarious hardware components and/or may perform various algorithms thatprovide the means for receiving a second ACK/NACK signal from the set ofsubordinate entities in an ACK portion of the second subframe, thesecond ACK/NACK signal comprising acknowledgment informationcorresponding to the data information.

The processor 1104 may also include a reference signal transmittingcircuit 1148. The reference signal transmitting circuit 1148 may includevarious hardware components and/or may perform various algorithms thatprovide the means for transmitting a reference signal in a referencesignal portion of a second subframe, where a duration of the referencesignal portion is less than a duration of a full symbol in the secondsubframe.

The processor 1104 may also include an ACK/NACK signal processingcircuit 1150. The ACK/NACK signal processing circuit 1150 may includevarious hardware components and/or may perform various algorithms thatprovide the means for processing a first ACK/NACK signal during aduration of a reference signal portion of a second subframe.

The processor 1104 may also include a switching period determiningcircuit 1152. The switching period determining circuit 1152 may includevarious hardware components and/or may perform various algorithms thatprovide the means for determining a DL to UL switching period associatedwith the one or more subordinate entities.

The processor 1104 may also include a propagation delay determiningcircuit 1154. The propagation delay determining circuit 1154 may includevarious hardware components and/or may perform various algorithms thatprovide the means for determining a signal propagation delay periodbetween the scheduling entity and the one or more subordinate entities.

The processor 1104 may also include a symbol dividing circuit 1156. Thesymbol dividing circuit 1156 may include various hardware componentsand/or may perform various algorithms that provide the means fordividing a full symbol in a subframe into a plurality of scaled symbols,at least one of the plurality of scaled symbols having a duration thatis equal to or greater than a total of the DL to UL switching period andthe signal propagation delay period.

The foregoing description provides a non-limiting example of theprocessor 1104 of the apparatus 1102. Although various circuits 1140,1142, 1144, 1146, 1148, 1150, 1152, 1154, and 1156 are described above,one of ordinary skill in the art will understand that the processor 1104may also include various other circuits 1158 that are in addition and/oralternative(s) to the aforementioned circuits 1140, 1142, 1144, 1146,1148, 1150, 1152, 1154, and 1156. Such other circuits 1158 may providethe means for performing any one or more of the functions, methods,processes, features and/or aspects described herein.

The computer-readable medium 1106 may include variouscomputer-executable instructions. The computer-executable instructionsmay include computer-executable code configured to perform variousfunctions and/or enable various aspects described herein. Thecomputer-executable instructions may be executed by various hardwarecomponents (e.g., the processor 1104 and/or any of its circuits 1140,1142, 1144, 1146, 1148, 1150, 1152, 1154, 1156, and 1158) of theapparatus 1102. The computer- executable instructions may be a part ofvarious software programs and/or software modules.

The computer-readable medium 1106 may include control informationtransmitting instructions 1160. In one example, the control informationtransmitting instructions 1160 may include computer-executableinstructions configured for transmitting control information in acontrol portion of a subframe, the control information corresponding todata information within the subframe. In another example, the controlinformation transmitting instructions 1160 may includecomputer-executable instructions configured for transmitting controlinformation in a control information portion of a second subframe thatis subsequent to the reference signal portion of the second subframe,wherein a duration of the control information portion is less than theduration of a full symbol in the second subframe.

The computer-readable medium 1106 may also include data informationtransmitting instructions 1162. The data information transmittinginstructions 1162 may include computer-executable instructionsconfigured for transmitting the data information in a data portion of asubframe.

The computer-readable medium 1106 may also include pilot signalreceiving instructions 1164. The pilot signal receiving instructions1164 may include computer- executable instructions configured forreceiving a pilot signal from the set of subordinate entities in a pilotportion of the subframe.

The computer-readable medium 1106 may also include ACK/NACK signalreceiving instructions 1166. In one example, the ACK/NACK signalreceiving instructions 1166 may include computer-executable instructionsconfigured for receiving an ACK/NACK signal from the set of subordinateentities in an ACK portion of the subframe, the ACK portion beingsubsequent to the pilot portion of the subframe, the ACK/NACK signalincluding acknowledgment information corresponding to the datainformation. In another example, the ACK/NACK signal receivinginstructions 1166 may include computer-executable instructionsconfigured for receiving a first ACK/NACK signal from a set ofsubordinate entities in a first subframe. In such example, the ACK/NACKsignal receiving instructions 1166 may also include computer-executableinstructions configured for receiving a second ACK/NACK signal from theset of subordinate entities in an ACK portion of the second subframe,the second ACK/NACK signal comprising acknowledgment informationcorresponding to the data information.

The computer-readable medium 1106 may also include reference signaltransmitting instructions 1168. The reference signal transmittinginstructions 1168 may include computer-executable instructionsconfigured for transmitting a reference signal in a reference signalportion of a second subframe, where a duration of the reference signalportion is less than a duration of a full symbol in the second subframe.

The computer-readable medium 1106 may also include ACK/NACK signalprocessing instructions 1170. The ACK/NACK signal processinginstructions 1170 may include computer-executable instructionsconfigured for processing a first ACK/NACK signal during a duration of areference signal portion of a second subframe.

The computer-readable medium 1106 may also include switching perioddetermining instructions 1172. The switching period determininginstructions 1172 may include computer-executable instructionsconfigured for determining a DL to UL switching period associated withthe one or more subordinate entities.

The computer-readable medium 1106 may also include propagation delaydetermining instructions 1174. The propagation delay determininginstructions 1174 may include computer-executable instructionsconfigured for determining a signal propagation delay period between thescheduling entity and the one or more subordinate entities.

The computer-readable medium 1106 may also include symbol dividinginstructions 1176. The symbol dividing instructions 1176 may includecomputer- executable instructions configured for dividing a full symbolin a subframe into a plurality of scaled symbols, at least one of theplurality of scaled symbols having a duration that is equal to orgreater than a total of the DL to UL switching period and the signalpropagation delay period.

The foregoing description provides a non-limiting example of thecomputer- readable medium 1106 of the apparatus 1102. Although variouscomputer-executable instructions 1160, 1162, 1164, 1166, 1168, 1170,1172, 1174, and 1176 are described above, one of ordinary skill in theart will understand that the computer-readable medium 1106 may alsoinclude various other computer-executable instructions 1178 that are inaddition and/or alternative(s) to the aforementioned computer-executableinstructions 1160, 1162, 1164, 1166, 1168, 1170, 1172, 1174, and 1176.Such other computer-executable instructions 1178 may be configured forany one or more of the functions, methods, processes, features and/orexamples described herein.

The memory 1105 may include various memory modules. The memory modulesmay be configured to store, and have read therefrom, various valuesand/or information by the processor 1104, or any of its circuits 1140,1142, 1144, 1146, 1148, 1150, 1152, 1154, 1156, and 1158. The memorymodules may also be configured to store, and have read therefrom,various values and/or information upon execution of thecomputer-executable code included in the computer-readable medium 1106,or any of its instructions 1160, 1162, 1164, 1166, 1168, 1170, 1172,1174, and 1176. The memory 1105 may include the previously discusseddata information, control information, and/or a duration of a fullsymbol in a subframe. The foregoing description provides a non- limitingexample of the memory 1105 of the apparatus 1102. Although various typesof data of the memory 1105 are described above, one of ordinary skill inthe art will understand that the memory 1105 may also include variousother data that are in addition and/or alternative(s) to theaforementioned data. Such other data may be associated with any one ormore of the functions, methods, processes, features and/or examplesdescribed herein.

FIG. 12 is a diagram 1200 illustrating an example of various methodsand/or processes according to some aspects of the present disclosure.The methods and/or processes may be performed by an apparatus. In someconfigurations, such an apparatus is the apparatus 1102 described abovewith reference to FIG. 11. In some configurations, such an apparatus isscheduling entity 202 (described above).

At block 1202, the apparatus transmits control information in a controlportion of the subframe, the control information corresponding to datainformation within the subframe. For example, with reference to FIG. 6,the control portion may be the control information portion 602. Here,when control information corresponds to data information, broadly, thismay refer to the control information providing scheduling informationfor scheduling resources corresponding to the data information;modulation and coding information, or other information relating to thedata information to enable a receiving device to receive and decode thedata information; status information relating to the data information,such as whether the data information is a retransmission; or othersimilar control information as would be recognized by those of ordinaryskill in the art.

At block 1204, the apparatus transmits the data information in a dataportion of the subframe. For example, with reference to FIG. 6, the dataportion may be the DL data portion 604.

At block 1206, the apparatus receives a pilot signal from the set ofsubordinate entities in a pilot portion of the subframe. For example,with reference to FIG. 6, the pilot portion may be the first scaledsymbol 625.

At block 1208, the apparatus receives an ACK/NACK signal from the set ofsubordinate entities in an ACK portion of the subframe, the ACK portionbeing subsequent to the pilot portion of the subframe, the ACK/NACKsignal including acknowledgment information corresponding to the datainformation. For example, with reference to FIG. 6, the ACK portion maybe the second scaled symbol 629. Here, when the ACK/NACK signal includesacknowledgment information corresponding to the data information,broadly, this refers to the ACK/NACK being configured to acknowledge, ornot, the decoding and verification of corresponding packets or transportblocks included in the data information.

FIG. 13 is a diagram 1300 illustrating an example of various methodsand/or processes according to some aspects of the present disclosure.The methods and/or processes may be performed by an apparatus. In someconfigurations, such an apparatus is the apparatus 1102 described abovewith reference to FIG. 11. In some configurations, such an apparatus isscheduling entity 202 (described above).

At block 1302, the apparatus receives a first ACK/NACK signal from theset of subordinate entities in a preceding subframe. For example, withreference to FIG. 8, the apparatus may receive a pilot and ACK/NACKsignal from a subordinate entity in symbols 14 and/or 15 of the subframe801. Therefore, in this example, the subframe 801 may be considered apreceding subframe with respect to subframe 803.

At block 1304, the apparatus transmits a reference signal in a referencesignal portion of the subframe. In one example, the reference signal maybe a CRS. In another example, the reference signal may be a demodulationreference signal (DMRS) or channel state information reference signal(CSI-RS). For example, with reference to FIG. 8, the apparatus maytransmit a CRS, DMRS, and/or CSI-RS in the reference signal portion 820of the subframe 803. In one example, a duration of the reference signalportion 820 is less than the duration of one symbol in the subframe.

At block 1306, the apparatus processes the first ACK/NACK signal duringthe duration of the reference signal portion of the subframe. Forexample, with reference to FIG. 8, the apparatus may process the firstACK/NACK signal during the first duration 826 of the first scaled symbol817.

At block 1308, the apparatus transmits control information in a controlinformation portion of the subframe that is subsequent to the referencesignal portion of the subframe. For example, with reference to FIG. 8,the apparatus may transmit control information in the control portion824 of the subframe 803. In one example, a duration of the controlinformation portion 824 is less than the duration of one symbol in thesubframe.

At block 1310, the apparatus transmits the data information in a dataportion of the subframe.

At block 1312, the apparatus receives a second ACK/NACK signal from theset of subordinate entities in an ACK portion of the subframe. Forexample, with reference to FIG. 8, the apparatus may receive a secondACK/NACK signal in symbol 15 of the subframe 803. In one example, thesecond ACK/NACK signal includes acknowledgment information correspondingto the data information. In one example, the reference signal portion,the control information portion, the data portion, and the ACK portionare contained in the same subframe.

FIG. 14 is a diagram 1400 illustrating an example of various methodsand/or processes according to some aspects of the present disclosure.The methods and/or processes may be performed by an apparatus. In someconfigurations, such an apparatus is the apparatus 1102 described abovewith reference to FIG. 11. In some configurations, such an apparatus isscheduling entity 202 (described above). It should be understood thatblocks represented with dotted lines represent optional blocks.

At block 1402, the apparatus determines a DL to UL switching periodassociated with the one or more subordinate entities. For example, theDL to UL switching period may be an RF switching time, which representsthe duration required for the apparatus to change its RF antennadirection.

At block 1404, the apparatus determines a signal propagation delayperiod between the scheduling entity and the one or more subordinateentities (for example, from a base station or eNode B to a UE). Forexample, the signal propagation delay period may be the RTT of a signalbetween a transmitter and receiver, which may be determined by doublingthe timing advance (TA) value.

At block 1406, the apparatus divides a full symbol in the subframe intoa plurality of scaled symbols, at least one of the plurality of scaledsymbols having a duration that is equal to or greater than a total ofthe DL to UL switching period and the signal propagation delay period.For example, with reference to FIG. 9, the apparatus may divide the fullOFDM symbol 904 having a duration of 28 μs by a factor of two togenerate two scaled symbols 908 and 910 having a duration of 14 μs for acase where the total of the DL to UL switching period and the signalpropagation delay period is less than or equal to 14 μs, hence GP onlyhas to be 14us instead another full symbol. As another example, withreference to FIG. 10, the apparatus may divide the full OFDM symbol 1004having a duration of 28 is by a factor of three to generate three scaledsymbols 1008, 1010, and 1012 having a duration of approximately 9.3 μsfor a case where the total of the DL to UL switching period and thesignal propagation delay period is less than or equal to 9.3 μs, whichleads to a GP of 9.3 μs instead of >31.25 μs. In one example, each ofthe plurality of scaled symbols are allocated less tones than the fullOFDM symbol. In one example, each of the plurality of scaled symbolshave a same duration.

At block 1408, the apparatus transmits data information to the one ormore subordinate entities in one or more of the plurality of scaledsymbols. In one example, the at least one of the plurality of scaledsymbols serves as a guard period.

FIG. 15 is a diagram illustrating an example of a hardwareimplementation of an apparatus 1502 according to some aspects of thepresent disclosure. Generally, the apparatus 1502 may be any deviceconfigured for wireless communication. In some configurations, theapparatus 1502 may be the subordinate entity 204, as described ingreater detail above. The apparatus 1502 may include a user interface1512. The user interface 1512 may be configured to receive one or moreinputs from a user of the apparatus 1502. The user interface 1512 mayalso be configured to display information to the user of the apparatus1502. The user interface 1512 may exchange data via the bus interface1508.

The apparatus 1502 may also include a transceiver 1510. The transceiver1510 may be configured to receive data and/or transmit data incommunication with another apparatus. The transceiver 1510 provides ameans for communicating with another apparatus via a wired or wirelesstransmission medium. In some configurations, the transceiver 1110 mayprovide the means for communicating with various other apparatus over atransmission medium. According to aspects of the present disclosure, theterm(s) ‘communicate’ and/or ‘communicating’ refer to at least one of atransmission or a reception. In other words, without deviating from thescope of the present disclosure, the term(s) ‘communicate’ and/or‘communicating’ may refer to a transmission without asimultaneous/concurrent reception, a reception without asimultaneous/concurrent transmission, and/or a transmission with asimultaneous/concurrent reception.

In some examples, the transceiver 1510 may provide the apparatus 1502with the means for transmitting data (e.g., pilot signal, ACK/NACKsignal) to the scheduling entity 202 as well as the means for receivingdata (e.g., control information, data information) from schedulingentity 202 (e.g., in a subframe). The transceiver 1510 may be configuredto perform such communications using various types of technologies, asdescribed in greater detail above. One of ordinary skill in the art willunderstand that many types of technologies may perform suchcommunication without deviating from the scope of the presentdisclosure.

The apparatus 1502 may also include a memory 1505, one or moreprocessors 1504, a computer-readable medium 1506, and a bus interface1508. The bus interface 1508 may provide an interface between a bus 1503and the transceiver 1510. The memory 1505, the one or more processors1504, the computer-readable medium 1506, and the bus interface 1508 maybe connected together via the bus 1503. The processor 1504 may becommunicatively coupled to the transceiver 1510 and/or the memory 1505.

The processor 1504 may include a control information receiving circuit1540. The control information receiving circuit 1540 may include varioushardware components and/or may perform various algorithms that providethe means for receiving control information in a control portion of thesubframe, the control information corresponding to data informationwithin the subframe.

The processor 1104 may also include a data information receiving circuit1542. The data information receiving circuit 1542 may include varioushardware components and/or may perform various algorithms that providethe means for receiving the data information in a data portion of thesubframe.

The processor 1104 may also include a pilot signal transmitting circuit1544. The pilot signal transmitting circuit 1544 may include varioushardware components and/or may perform various algorithms that providethe means for transmitting a pilot signal to the scheduling entity 202in a pilot portion of the subframe. The processor 1104 may also includea data information processing circuit 1546. The data informationprocessing circuit 1546 may include various hardware components and/ormay perform various algorithms that provide the means for processing thedata information received in a final symbol of the data portion of thesubframe within the total duration of the guard period portion of thesubframe and the pilot portion of the subframe.

The processor 1104 may also include an ACK/NACK signal transmittingcircuit 1548. The ACK/NACK signal transmitting circuit 1548 may includevarious hardware components and/or may perform various algorithms thatprovide the means for transmitting an ACK/NACK signal to the schedulingentity 202 in an ACK portion of the subframe, the ACK portion beingsubsequent to the pilot portion of the subframe. The ACK/NACK signalincludes acknowledgment information corresponding to the datainformation.

The foregoing description provides a non-limiting example of theprocessor 1104 of the apparatus 1102. Although various circuits 1540,1542, 1544, 1546, and 1548 are described above, one of ordinary skill inthe art will understand that the processor 1104 may also include variousother circuits 1550 that are in addition and/or alternative(s) to theaforementioned circuits 1540, 1542, 1544, 1546, and 1548. Such othercircuits 1550 may provide the means for performing any one or more ofthe functions, methods, processes, features and/or aspects describedherein.

The computer-readable medium 1506 may include variouscomputer-executable instructions. The computer-executable instructionsmay include computer-executable code configured to perform variousfunctions and/or enable various aspects described herein. Thecomputer-executable instructions may be executed by various hardwarecomponents (e.g., the processor 1504 and/or any of its circuits 1540,1542, 1544, 1546, 1548 and 1550) of the apparatus 1502. Thecomputer-executable instructions may be a part of various softwareprograms and/or software modules. The computer-readable medium 1506 mayinclude control information receiving instructions 1552. The controlinformation receiving instructions 1552 may include computer-executableinstructions configured for receiving control information in a controlportion of the subframe, the control information corresponding to datainformation within the subframe.

The computer-readable medium 1506 may also include data informationreceiving instructions 1554. The data information receiving instructions1554 may include computer-executable instructions configured forreceiving the data information in a data portion of the subframe.

The computer-readable medium 1506 may also include pilot signaltransmitting instructions 1556. The pilot signal transmittinginstructions 1556 may include computer-executable instructionsconfigured for transmitting a pilot signal to the scheduling entity 202in a pilot portion of the subframe.

The computer-readable medium 1508 may also include data informationprocessing instructions 1558. The data information processinginstructions 1558 may include computer-executable instructionsconfigured for processing the data information received in a finalsymbol of the data portion of the subframe within the total duration ofthe guard period portion of the subframe and the pilot portion of thesubframe.

The computer-readable medium 1508 may also include ACK/NACK signaltransmitting instructions 1560. The ACK/NACK signal transmittinginstructions 1560 may include computer-executable instructionsconfigured for transmitting an ACK/NACK signal to the scheduling entityin an ACK portion of the subframe, the ACK portion being subsequent tothe pilot portion of the subframe. The ACK/NACK signal includesacknowledgment information corresponding to the data information

The foregoing description provides a non-limiting example of thecomputer- readable medium 1106 of the apparatus 1102. Although variouscomputer-executable instructions 1540, 1542, 1544, 1546, and 1548 aredescribed above, one of ordinary skill in the art will understand thatthe computer-readable medium 1506 may also include various othercomputer-executable instructions 1562 that are in addition and/oralternative(s) to the aforementioned computer-executable instructions1540, 1542, 1544, 1546, and 1548. Such other computer-executableinstructions 1562 may be configured for any one or more of thefunctions, methods, processes, features and/or aspects described herein.

The memory 1505 may include various memory modules. The memory modulesmay be configured to store, and have read therefrom, various valuesand/or information by the processor 1504, or any of its circuits 1540,1542, 1544, 1546, 1548, and 1560. The memory modules may also beconfigured to store, and have read therefrom, various values and/orinformation upon execution of the computer-executable code included inthe computer-readable medium 1506, or any of its instructions 1540,1542, 1544, 1546, 1548, and 1560. The foregoing description provides anon-limiting example of the memory 1505 of the apparatus 1502. Althoughvarious types of data of the memory 1505 are described above, one ofordinary skill in the art will understand that the memory 1505 may alsoinclude various other data that are in addition and/or alternative(s) tothe aforementioned data. Such other data may be associated with any oneor more of the functions, methods, processes, features and/or aspectsdescribed herein.

By way of example, an element, or any portion of an element, or anycombination of elements may be implemented with a “processing system”(e.g., processing system 1114, 1514) that includes one or moreprocessors (e.g., processors 1104, 1504). Examples of processors includemicroprocessors, microcontrollers, digital signal processors (DSPs),field programmable gate arrays (FPGAs), programmable logic devices(PLDs), state machines, gated logic, discrete hardware circuits, andother suitable hardware configured to perform the various functionalitydescribed throughout this disclosure. One or more processors in theprocessing system may execute software. Software shall be construedbroadly to mean instructions, instruction sets, code, code segments,program code, programs, subprograms, software modules, applications,software applications, software packages, routines, subroutines,objects, executables, threads of execution, procedures, functions, etc.,whether referred to as software, firmware, middleware, microcode,hardware description language, or otherwise.

Accordingly, in one or more exemplary embodiments, the functionsdescribed may be implemented in hardware, software, firmware, or anycombination thereof. If implemented in software, the functions may bestored on or encoded as one or more instructions or code on acomputer-readable medium. Computer-readable media includes computerstorage media. Storage media may be any available media that can beaccessed by a computer. By way of example, and not limitation, suchcomputer-readable media can include random access memory (RAM), a readonly memory (ROM), a programmable ROM (PROM), an erasable PROM (EPROM),an electrically erasable PROM (EEPROM), optical disk storage, magneticdisk storage or other magnetic storage devices, or any other medium thatcan be used to carry or store desired program code in the form ofinstructions or data structures and that can be accessed by a computer.Disk and disc, as used herein, includes compact disc (CD), laser disc,optical disc, digital versatile disc (DVD), and floppy disk where disksusually reproduce data magnetically, while discs reproduce dataoptically with lasers. Combinations of the above should also be includedwithin the scope of computer-readable media.

FIG. 16 is a diagram 1600 illustrating an example of various methodsand/or processes according to some aspects of the present disclosure.The methods and/or processes may be performed by an apparatus. In someconfigurations, such an apparatus is the apparatus 1502 described abovewith reference to FIG. 15. In some configurations, such an apparatus issubordinate entity 204 (described above). It should be understood thatblocks indicated with dotted lines represent optional blocks.

At block 1602, the apparatus receives control information in a controlportion of the subframe, the control information corresponding to datainformation within the subframe. For example, with reference to FIG. 6,the control portion may be the control information portion 602. Here,when control information corresponds to data information, broadly, thisrefers to the control information providing scheduling information forscheduling resources corresponding to the data information; modulationand coding information, or other information relating to the datainformation to enable a receiving device to receive and decode the datainformation; status information relating to the data information, suchas whether the data information is a retransmission; or other similarcontrol information as would be recognized by those of ordinary skill inthe art.

At block 1604, the apparatus receives the data information in a dataportion of the subframe. For example, with reference to FIG. 6, the dataportion may be the DL data portion 604.

At block 1606, the apparatus transmits a pilot signal from the set ofsubordinate entities in a pilot portion of the subframe. For example,with reference to FIG. 6, the pilot portion may be the first scaledsymbol 625 having the third duration 638.

At block 1608, the apparatus processes the data information received ina final symbol of the data portion of the subframe within a totalduration of the guard period portion of the subframe and the pilotportion of the subframe.

At block 1610, the apparatus transmits an ACK/NACK signal from the setof subordinate entities in an ACK portion of the subframe, the ACKportion being subsequent to the pilot portion of the subframe, theACK/NACK signal including acknowledgment information corresponding tothe data information. For example, with reference to FIG. 6, the ACKportion may be the second scaled symbol 629 having the fourth duration640. Here, when the ACK/NACK signal includes acknowledgment informationcorresponding to the data information, broadly, this refers to theACK/NACK being configured to acknowledge, or not, the decoding andverification of corresponding packets or transport blocks included inthe data information.

The various aspects disclosed herein provide scaled symbols having aduration that is less than a full OFDM symbol. As previously discussed,such scaled symbols may provide fine symbol granularity for reducing aTDD processing timeline. For example, multiple scaled symbols may beconfigured from the time duration of one full OFDM symbol, and one ormore of these scaled symbols may be allocated for pilot prescheduling inorder to provide additional processing time and, therefore, improve theprocessing timeline. The use of the scaled symbols require approximatelythe same transmission power as a full OFDM symbol, thereby maintainingthe same link-budget as a full OFDM symbol. Transmission and receptionprocessing may be facilitated due to the same sampling rate with thescaled symbols and the scaled down FFT size. Efficient interferencemanagement may be achieved by implementing synchronous scaled symbolsacross all subordinate entities for interference management (no ICI forsynchronous thin-symbol). In one example, different symbol scalingmultiplexing may be used with different subordinate entities (e.g., datavs. control). Controlled interference management may be achieved throughguardband and WOLA.

As those skilled in the art will readily appreciate, various aspectsdescribed throughout this disclosure may be extended to any suitabletelecommunication system, network architecture, and communicationstandard. By way of example, various aspects may be applied to UMTSsystems such as W-CDMA, TD-SCDMA, and TD-CDMA. Various aspects may alsobe applied to systems employing Long Term Evolution (LTE) (in FDD, TDD,or both modes), LTE-Advanced (LTE-A) (in FDD, TDD, or both modes),CDMA2000, Evolution-Data Optimized (EV-DO), Ultra Mobile Broadband(UMB), IEEE 802.11 (Wi-Fi), IEEE 802.16 (WiMAX), IEEE 802.20,Ultra-Wideband (UWB), Bluetooth, and/or other suitable systems,including those described by yet-to-be defined wide area networkstandards. The actual telecommunication standard, network architecture,and/or communication standard employed will depend on the specificapplication and the overall design constraints imposed on the system.

Within the present disclosure, the word “exemplary” is used to mean“serving as an example, instance, or illustration.” Any implementationor aspect described herein as “exemplary” is not necessarily to beconstrued as preferred or advantageous over other aspects of thedisclosure. Likewise, the term “aspects” does not require that allaspects of the disclosure include the discussed feature, advantage ormode of operation. The term “coupled” is used herein to refer to thedirect or indirect coupling between two objects. For example, if objectA physically touches object B, and object B touches object C, thenobjects A and C may still be considered coupled to one another—even ifthey do not directly physically touch each other. For instance, a firstdie may be coupled to a second die in a package even though the firstdie is never directly physically in contact with the second die. Theterms “circuit” and “circuitry” are used broadly, and intended toinclude both hardware implementations of electrical devices andconductors that, when connected and configured, enable the performanceof the functions described in the present disclosure, without limitationas to the type of electronic circuits, as well as softwareimplementations of information and instructions that, when executed by aprocessor, enable the performance of the functions described in thepresent disclosure.

One or more of the components, steps, features and/or functionsillustrated in FIGS. 1-16 may be rearranged and/or combined into asingle component, step, feature or function or embodied in severalcomponents, steps, or functions. Additional elements, components, steps,and/or functions may also be added without departing from novel featuresdisclosed herein. The apparatus, devices, and/or components illustratedin FIGS. 1-16 may be configured to perform one or more of the methods,features, or steps described herein. The novel algorithms describedherein may also be efficiently implemented in software and/or embeddedin hardware.

It is to be understood that the specific order or hierarchy of steps inthe methods disclosed is an illustration of exemplary processes. Basedupon design preferences, it is understood that the specific order orhierarchy of steps in the methods may be rearranged. The accompanyingmethod claims present elements of the various steps in a sample order,and are not meant to be limited to the specific order or hierarchypresented unless specifically recited therein.

The previous description is provided to enable any person skilled in theart to practice the various aspects described herein. Variousmodifications to these aspects will be readily apparent to those skilledin the art, and the generic principles defined herein may be applied toother aspects. Thus, the claims are not intended to be limited to theaspects shown herein, but are to be accorded the full scope consistentwith the language of the claims, wherein reference to an element in thesingular is not intended to mean “one and only one” unless specificallyso stated, but rather “one or more.” Unless specifically statedotherwise, the term “some” refers to one or more. A phrase referring to“at least one of” a list of items refers to any combination of thoseitems, including single members. As an example, “at least one of: a, b,or c” is intended to cover: a; b; c; a and b; a and c; b and c; and a, band c. All structural and functional equivalents to the elements of thevarious aspects described throughout this disclosure that are known orlater come to be known to those of ordinary skill in the art areexpressly incorporated herein by reference and are intended to beencompassed by the claims. Moreover, nothing disclosed herein isintended to be dedicated to the public regardless of whether suchdisclosure is explicitly recited in the claims. No claim element is tobe construed under the provisions of 35 U.S.C. §112 (0, unless theelement is expressly recited using the phrase “means for” or, in thecase of a method claim, the element is recited using the phrase “stepfor.”

What is claimed is:
 1. A method of wireless communication in asynchronous network for a scheduling entity to communicate with a set ofone or more subordinate entities utilizing a time division duplex (TDD)carrier, wherein the TDD carrier comprises a subframe, the methodcomprising: transmitting control information in a control portion of thesubframe, the control information corresponding to data informationwithin the subframe; transmitting the data information in a data portionof the subframe; receiving a pilot signal from the set of subordinateentities in a pilot portion of the subframe; and receiving anacknowledged (ACK)/not acknowledged (NACK) signal from the set ofsubordinate entities in an ACK portion of the subframe, the ACK portionbeing subsequent to the pilot portion of the subframe, the ACK/NACKsignal comprising acknowledgment information corresponding to the datainformation, wherein the control portion, the data portion, the pilotportion, and the ACK portion are contained in the same subframe.
 2. Themethod of claim 1, wherein the subframe comprises a guard period portionafter the data portion and before the pilot portion, wherein a totalduration of the guard period portion and the pilot portion is greaterthan or equal to an approximate duration of a full symbol in thesubframe.
 3. The method of claim 2, wherein the total duration of theguard period portion and the pilot portion allows the set of subordinateentities sufficient time to process the data information transmitted ina final symbol of the data portion of the subframe.
 4. The method ofclaim 2, wherein a duration of the guard period portion is less than theduration of one symbol in the subframe.
 5. The method of claim 2,wherein the subframe comprises a second guard period portion after theACK portion of the subframe, wherein a duration of the second guardperiod portion is less than the duration of a full symbol in thesubframe.
 6. The method of claim 5, wherein the duration of the secondguard period portion allows the scheduling entity sufficient time toprocess the ACK/NACK signal.
 7. The method of claim 1, wherein the pilotportion comprises a first cyclic prefix (CP) and the ACK portioncomprises a second CP.
 8. The method of claim 1, wherein a duration ofthe pilot portion of the subframe is different from a duration of theACK portion of the subframe.
 9. A scheduling entity configured to managea wireless communication network, comprising: a processor; a transceivercommunicatively coupled to the processor; and a memory communicativelycoupled to the processor, wherein the processor and the memory areconfigured to: transmit control information in a control portion of asubframe, the control information corresponding to data informationwithin the subframe; transmit the data information in a data portion ofthe subframe; receive a pilot signal from a set of subordinate entitiesin a pilot portion of the subframe; and receive an acknowledged(ACK)/not acknowledged (NACK) signal from the set of subordinateentities in an ACK portion of the subframe, the ACK portion beingsubsequent to the pilot portion of the subframe, the ACK/NACK signalcomprising acknowledgment information corresponding to the datainformation, wherein the control portion, the data portion, the pilotportion, and the ACK portion are contained in the same subframe.
 10. Thescheduling entity of claim 9, wherein the subframe comprises a guardperiod portion after the data portion and before the pilot portion,wherein a total duration of the guard period portion and the pilotportion is greater than or equal to a duration of a full symbol in thesubframe.
 11. The scheduling entity of claim 10, wherein the totalduration of the guard period portion and the pilot portion allows theset of subordinate entities sufficient time to process the datainformation transmitted in a final symbol of the data portion of thesubframe.
 12. The scheduling entity of claim 10, wherein a duration ofthe guard period portion is less than the duration of a full symbol inthe subframe.
 13. The scheduling entity of claim 10, wherein thesubframe comprises a second guard period portion after the ACK portionof the subframe, wherein a duration of the second guard period portionis less than the duration of a full symbol in the subframe.
 14. Thescheduling entity of claim 13, wherein the duration of the second guardperiod portion allows the scheduling entity sufficient time to processthe ACK/NACK signal.
 15. The scheduling entity of claim 9, wherein thepilot portion comprises a first cyclic prefix (CP) and the ACK portioncomprises a second CP.
 16. The scheduling entity of claim 9, wherein aduration of the pilot portion of the subframe is different from aduration of the ACK portion of the subframe.
 17. A method of wirelesscommunication in a synchronous network for a scheduling entity tocommunicate with a set of one or more subordinate entities utilizing atime division duplex (TDD) carrier, wherein the TDD carrier comprises asubframe, the method comprising: receiving a first acknowledged(ACK)/not acknowledged (NACK) signal from the set of subordinateentities in a first subframe; transmitting a reference signal in areference signal portion of a second subframe, wherein a duration of thereference signal portion is less than a duration of a full symbol in thesecond subframe; and transmitting control information in a controlinformation portion of the second subframe that is subsequent to thereference signal portion of the second subframe, wherein a duration ofthe control information portion is less than the duration of a fullsymbol in the second subframe.
 18. The method of claim 17, furthercomprising processing the first ACK/NACK signal during the duration ofthe reference signal portion of the second subframe.
 19. The method ofclaim 17, wherein the control information corresponds to datainformation within the second subframe, further comprising: transmittingthe data information in a data portion of the second subframe; andreceiving a second ACK/NACK signal from the set of subordinate entitiesin an ACK portion of the second subframe, the second ACK/NACK signalcomprising acknowledgment information corresponding to the datainformation, wherein the reference signal portion, the controlinformation portion, the data portion, and the ACK portion are containedin the same subframe.
 20. The method of claim 17, wherein the referencesignal comprises a cell specific reference signal (CRS), a demodulationreference signal (DMRS), and/or a channel state information referencesignal (CSI-RS).
 21. The method of claim 17, wherein a duration of theRS portion of the second subframe allows the scheduling entitysufficient time to process the first ACK/NACK signal before a controlchannel symbol is formed.
 22. The method of claim 17, wherein thereference signal portion of the second subframe comprises a first cyclicprefix (CP) and the control information portion of the second subframecomprises a second CP.
 23. The method of claim 17, wherein a duration ofthe reference signal portion of the second subframe is different from aduration of the control information portion of the second subframe. 24.A scheduling entity configured to manage a wireless communicationnetwork, comprising: a processor; a transceiver communicatively coupledto the processor; and a memory communicatively coupled to the processor,wherein the processor and the memory are configured to: receive a firstacknowledged (ACK)/not acknowledged (NACK) signal from a set ofsubordinate entities in a first subframe; transmit a reference signal ina reference signal portion of a second subframe, wherein a duration ofthe reference signal portion is less than a duration of a full symbol inthe second subframe; and transmit control information in a controlinformation portion of the second subframe that is subsequent to thereference signal portion of the second subframe, wherein a duration ofthe control information portion is less than the duration of a fullsymbol in the second subframe.
 25. The scheduling entity of claim 24,wherein the processor and the memory are configured to: process thefirst ACK/NACK signal during the duration of the reference signalportion of the second subframe.
 26. The scheduling entity of claim 24,wherein the control information corresponds to data information withinthe second subframe, and wherein the processor and the memory areconfigured to: transmit the data information in a data portion of thesecond subframe; and receive a second ACK/NACK signal from the set ofsubordinate entities in an ACK portion of the second subframe, thesecond ACK/NACK signal comprising acknowledgment informationcorresponding to the data information, wherein the reference signalportion, the control information portion, the data portion, and the ACKportion are contained in the same subframe.
 27. The scheduling entity ofclaim 24, wherein the reference signal comprises a cell specificreference signal (CRS), a demodulation reference signal (DMRS), and/or achannel state information reference signal (CSI-RS).
 28. The schedulingentity of claim 24, wherein a duration of the RS portion of the secondsubframe allows the scheduling entity sufficient time to process thefirst ACK/NACK signal before a control channel symbol is formed.
 29. Thescheduling entity of claim 24, wherein the reference signal portion ofthe second subframe comprises a first cyclic prefix (CP) and the controlinformation portion of the second subframe comprises a second CP. 30.The scheduling entity of claim 24, wherein a duration of the referencesignal portion of the second subframe is different from a duration ofthe control information portion of the second subframe.